Honestly I stopped watching when after the 10th time you let it bounce twice in less than 30 seconds...
If you can't hit 10 balls in a row without letting one bounce twice you should stand a little closer.
Make sure you're basic technique is right and don't overthink too much.
Than hit a lot of balls and when you are able to hit at least 100 balls without missing you can start changing minor things if necessary. http://www.fuzzyyellowballs.com/
This is a great site, take a look.

I think it's not good to stay too close to the wall for ground strokes. You will be rushed and will start making shortcuts with your technique.

i actually think it's ok to let the ball bounce twice, or hit harder/deeper so that it bounces once (i prefer this as it is more realistic). The key is to be consistent.